5. CN - V

Question 1

What are the 3 divisions of CN V, where they exit the brain, and their functions

Answer 1

V1: Opthalmic Division (superior orbital fissure)
Sensory to orbit, forehead, ant nose

V2: Maxillary Division (foramen rotundum)
Sensory to upper jaw + teeth, palate, nasal cavity

V3: Mandibular Division (foramen ovale)
Sensory to lower jaw + teeth
Branchiomotor to muscles of mastication

All 3 divisions pick up POST-synaptic PARASYMPS

Question 2

How do the following diseases affect CN V?
Trigeminal Neuralgia: Tic Douloreux

Herpes Zoster Infection

Answer 2

TN: Tic Douloreux - intense facial pain due to trigeminal nerve compression

Shingles: can affect all 3 divisions or just a single division

Question 3

What are the different nerves of V1 and where to they go? what types of fibers are they?

Answer 3

Frontal Nerve - Supraorbital N. and Supratrochlear N.
Lacrimal Nerve - to lacrimal gland (does NOT cause secretions)
Nasociliary Nerve - Anterior and Posterior Ethmoidal N. (nose sensory), Long/Short Ciliary N. (sensory to eyeball)

ALL are GENERAL SENSORY
Short Ciliary Nerve - picks up post-synaptic PARASYMPS from ciliary ganglion (CN 3)
Lacrimal Nerve (V1) - picks up post-synaptic PARASYMPS from V2 (zygomatic nerve) to trigger lacrimal gland secretions

Question 4

What types of fibers make up V2? What are the different nerves of V2 and where do they go? Where do they leave the skull? How is the nasal septum innervated?

Answer 4

ALL are GENERAL SENSORY - most pick up post-synaptic PARASYMPS from pterygopalatine ganglion
Pterygopalatine fossa: distribution point for V2
Ant PPF: via inferior orbital fissure - infraorbital and zygomatic nerves (upper jaw)
Med PPF: via sphenopalatine foramen - nasopalatine and lateral nasal n.
Inf PPF: greater + lesser palatine n. (tunnel to palate)
Lat. PPF: posterior superior alveolar nerves to molars

Nasal Septum:
V1: ant. ethmoidal branch of nasociliary n. innervates ant. nose
V2: nasopalatine nerve, lateral nasal nerves get post. and lat. nose

Question 5

What are the different nerves of V3 and where do they go?

Answer 5

General Sensory:
Inferior Alveolar Nerve: through mandibular canal -> Mental N. to lower jaw
Lingual: to tongue (picks up taste/parasymp from chorda tympani)
Buccal: to cheek
Auriculotemporal: above/in front of ear (picks up parasymps from CN IX from parotid gland)

Branchiomotor:
Mylohyoid - floor of oral cavity
Muscles of mastication

Question 6

What is the primordium for CN V? What is the pretrematic branch?

Answer 6

Pharyngeal Arch 1

Pretrematic: Opthalmic Division (V1)